Add GrOpList and rename GrDrawTarget to GrRenderTargetOpList

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=3910

Change-Id: I026aa26ecc61a0d002e98892dca728536259e8b1
Reviewed-on: https://skia-review.googlesource.com/3910
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
diff --git a/src/gpu/GrPrimitiveProcessor.h b/src/gpu/GrPrimitiveProcessor.h
index 00b4df0..561f54b 100644
--- a/src/gpu/GrPrimitiveProcessor.h
+++ b/src/gpu/GrPrimitiveProcessor.h
@@ -171,7 +171,7 @@
     const Attribute& getAttrib(int index) const { return fAttribs[index]; }
 
     // Returns the vertex stride of the GP.  A common use case is to request geometry from a
-    // drawtarget based off of the stride, and to populate this memory using an implicit array of
+    // GrOpList based off of the stride, and to populate this memory using an implicit array of
     // structs.  In this case, it is best to assert the vertexstride == sizeof(VertexStruct).
     size_t getVertexStride() const { return fVertexStride; }